Totalizer circuit for coin operated telephones

ABSTRACT

An electronic totalizer circuit which permits a coin telephone to be programmed for any desired initial deposit rate, and with minor modification to be used on telephones that provide prepay, semi-postpay and emergency calling modes of operation. The circuit is intended as a conversion unit for coin operated telephones lacking totalizing capabilities.

United States Patent Beeman et al.

1 1 Apr. 29, 1975 1 TOTALIZER CIRCUIT FOR (()IN 3.307.671 3/1967 Shirley1 14/1 N OPERATED TELEPHQNES 3.668.291) 6/1972 Robertson. Jr... 179/03 R3.703.229 ll/l972 llowring l 1 l94/l N 1 Inventors: Robert H- Bcemun.Berkeley: 3.760.101 1 1 /73 Burns 179/63 R Robert V. Burns. 'linleyPark. both 3.806.651 4/1974 Battriek 1 .1 179/115 ol lll. 3.814.9076/1974 Edington et al 179/03 R 173] Assignee: GTE Automatic ElectricLahommries lm-"rpwamd lrimury !:.\'umim'rKathleen H. (lally Nor/makeAss'ixlunl lixmninur-(ierald l.. Brigance P I I 0 t 26 I97 Allurm'y.Agent, or firm-Robert J. Black 1 CL c 1 [-1] Appl. No.. 409,998 ABSTRACTU Q 179/6 3 R An electronic totalizer circuit which permits a coin 6; k4r7102 telephone to he programmed for any desired initial delisxl Fie'ld1 h 4 6 posit rate, and with minor modification to he used on i Itelephones that provide prepay. semipostpay and i emergency callingmodes of operation. The circuit is H6] References (nod intended as aconversion unit for coin operated tele- UNITFD STATPQ PATFNTS phoneslacking totalizing capabilities.

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TOTALIZER CIRCUIT FOR COIN OPERATED TELEPHONES BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to a cointelephone circuit and more particularly to a variable initial depositrate totalizing circuit useful in prepay, semi-postpay and emergencycalling modes of operation in coin operated telephones.

2. Description of the Prior Art Most of the coin telephones now inoperation throughout the country are descendants of a design firstintroduced in 1912 by the originator of public telephones, The GrayTelephone Paystation Company. During its evolution the coin telephonehas seen incorporation of such features as dial operation, anti-sidetone transmission circuits, one piece hand set, conversion from 5 toservice, self compensating transmission networks, printed wiringtransmission networks, single coil prepay coin relays and touch callingoperation.

Among the more recent modifications of coin telephone design have beenthe inclusion of totalizer mechanisms which operate in response to thedeposit of coins to store coin deposit information during operation.Most embodiments of this device to date have been electromechanical innature and are typified by that disclosed in US. Pat. No. 3,435,146issued to E. R. Andregg and K. F. Voyles. Due to the size of theelectro-mechanical totalizer mechanism it is not readily adaptable forinclusion in coin telephones not particularly equipped for totalizers.

Accordingly is the object of the present invention to provide a cointelephone adapter circuit that incorporates electronic circuitry withthe attendant advantages of reduced size and economy for a programmabletotalizer, that is readily adapted for inclusion in existing cointelephones.

SUMMARY OF THE INVENTION The present invention is an electronictotalizer designed for addition to existing non-totalizer equipped cointelephones. The totalizer provides the following functions: Thetotalizer prevents the completion of all calls until the required amountof money up to a predetermined base rate has been deposited, except whenthe unit is modified to provide calls for the emergency calling feature.By means of strapping options any base rate may be selected as desiredin 5 increments. The present totalizer controls the existing coinoperated telephone circuitry and may be used with coin telephonesequipped with conventional rotary dials or touch calling units. Powerfor operating the totalizer is so low that it can be derived from thetelephone line with no penalty of loop length and no adjustments arerequired. As indicated previously various modifications of the circuitryof the present invention permit operation of the associated cointelephone in prepay, semipostpay and emergency calling modes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic circuit diagramof an electronic totalizer, adapted for inclusion in a coin operatedtelephone intended for operation in the prepay mode.

FIG. 2 is a schematic circuit diagram of an electronic totalizer adapterfor inclusion in a coin telephone intended for operation in thesemi-postpay mode.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prepay Operation Referringfirst to FIG. I a totalizer in accordance with the present invention isshown in a coin telephone equipped for Prepay Operation. In addition tothe totalizer, those portions of the coin telephone that are requiredfor operation of the totalizer circuitry are shown. Other portions notrequired have been eliminated from the drawing of FIG. I to simplify theunderstanding of the present invention.

Shown as a portion of the coin telephone circuit are terminals T and Rconnected to a telephone line extending to a telephone central office,dial 101 containing dial inpulsing springs, transmission network 103,receiver 104 and a transmitter 105. In addition the coin telephonecircuitry includes a switch hook 102 shown in its non-operated oron-hook" position, coin relay and its associated coin trigger springsIII and 112. Coin trigger springs 111 and 112 are shown in their normalposition. prior to the deposit of any coins in the telephone. Inaddition the coin telephone circuit includes coin operated switches 113and 114 which operate in response to the deposit of nickels and dimesrespectively. It should also be noted that these two springs are alsoshown in their normal or pre-coin deposit position.

The totalizer 100 consists of a power supply portion including diodes121 through 126 inclusive. resistors I31, 132 capacitor 133 and a zenerdiode 134. Also included in the totalizer 100 are a decimal decodercounter 160, which may be a standard integrated circuit counter used tocount and store information relative to the quantity and value ofdeposited coins. The counter circuitry may take several forms that arewell known and as such, the details thereof do not form a portion of thepresent invention.

Included in the totalizer and connected between the coin operatedswitches 113 and 114 is logic circuitry consisting of gate 150, inverter151 and capacitors 152 and 153 which provide an input from the coinoperated switches 113 and 114 to the decoder 160. The output of thedecoder is connected by strap 16] to gate 172, whose output is coupledthrough capacitor 173 to a bistable rate relay having associatedcontacts 171', Also included in the totalizer 100 is an optical isolatordevice 140 which provides a reset function for the counter.

For a further understanding of the present invention a description ofthe placement of a telephone call in a coin telephone of the prepay typein accordance with the present invention will be described.

Initially the subscriber will remove his hand set not shown, containingtransmitter 105 and receiver 104 from hook switch 102 causing it tocomplete a circuit for terminal T through dial 101, the transmissionnetwork 103, transmitter 105 and receiver 104, through the hook switchcontacts 102, to terminal R. The loop is now closed to the centraloffice preparing it for response to signals from the coin telephone.

At this time the subscriber wishing to place a call must deposit theproper amount of money in the coin slot of the coin operated telephone.It should be noted that in the present embodiment as shown, that thecounter output 20 lead is strapped by means of strap 161 to the input ofNOR gate 172. This strapping indicates that the initial or base rate foroperation of the present coin operated telephone is 20 Other base ratesmay be established by connection strap 161 to one of the other terminalssuch as the 5 etc. outputs of counter 160.

Assuming now that the customer deposits first a nickel, coin operatedswitch 113 will operate momentarily, connecting ground to one of theinputs of NOR gate 150. This causes an output pulse from NOR gate 150which is extended to counter 160 which normally has an output on thelead extending from the zero terminal lead. An output signal will now bepresent on the 5 output lead. Because it has no output connection, nosignal will be extended to NOR gate 172. With the output signal beingremoved from the zero output lead, this will cause gate 172 to producein a direction to cause operation of rate relay 170, which will becoupled to the relay by means of capacitor 173. Capacitor 173 willcharge and current flow to the relay 170 will cease. Relay 170 beingbistable will remain operated. At this time the operation of rate relay170 will cause operation of its associated contacts 171 placing a shortdirectly across the dial inpulse springs of dial 101 and opening theoperating path for coin relay 110.

When the initial coin deposit was made coin trigger springs 111 and 112also operated. Coin trigger spring 111 prepared an operating path toground for coin relay 110, while coin trigger springs ll2 opened toremove a previously existing short circuit across the dial 101. Thislatter short circuit path includes strap 115. If the coin operatedtelephone of the present invention is normally of the prepay type, butequipped for emergency calling, strap 115 would not be present and theshort circuit provided by that strap and the path through the cointrigger springs 112 would not be present. Permitting direct dialing ofemergency numbers without depositing of coins.

Recalling that a 20 i total deposit is required before dialing cancommence, the subscriber will now deposit a second nickle reoperatingcoin operated switch 113, and cause the advance of counter of 160 toproduce an output on the 10 1 output lead. It should also be noted thatcoin springs 111 and 112 will stay operated after the initial coindeposit and therefore no further action takes place involving theircircuitry at this time. At this time the subscriber deposits a dimeoperating coin operated switch 114. The resulting ground pulse throughthe circuitry of inverter 151 and associated capacitors 152 and 153 willcause NOR gate 150 to produce two output pulses to counter 160 causingit to advance its output from the l0 i to output terminal and from the15 output terminal to the output terminal. Because strap 161 isconnected between the 20 output terminal and the input of gate 172, NORgate 172 will produce a zero output, causing rate relay 170 to restoreclue to current produced by the charge stored in capacitor 175 flowingthrough relay 170 in a direction to cause it to restore. Afer the changeof capacitor 175 has dissipated relay 170 will remain restored since itis a bistable relay. At the same time an output from counter 160 wasextended to gate 172 the same output was also extended over a countinhibit lead back into the decimal counter 160 preventing it fromoperating further in response to deposit of any additional coins.

With the restoration of relay 170 a path will be completed from terminalT through break contacts 171 and through the light emitting diode thatforms a portion of optical isolator 140 to coin relay 110. Because cointrigger springs 11] were previously operated a path is now complete fromcoin relay 110 to ground. Completion of this path prepares coin relay110 for operation and extends ground over terminal T to the centraloffice to advise the central office equipment that a proper amount ofcoinage has been deposited in the coin operated telephone. When raterelay 170 restored the short was also removed from across the inpulsesprings of dial 101 by the opening of the make contact 171.

When the connection is established through contacts 171 from terminal T,to the light emitting diode of optical isolator 140, current from thetelephone central office will cause the light emitting diode to operate,turning on the associated photo transistor also included in opticalisolator 140. This operation will complete a path from battery to thereset lead of counter 160, causing it to reset to zero.

At this time the subscriber may now operate his dial to effect controlof the central office switching equipment to complete a connection to aselected subscriber.

After the subscriber has reached his party and completed his call, hereplaces the hand set including transmitter 105 and receiver 104 on hookswitch 102 opening the connections to the telephone central office. Coinbattery will now be returned from the central offree over the leadconnected to terminal T through break contact 171, and the opticalisolator 140 to coin relay causing it to operate at this time to collectthe previously deposited coins. It should be noted that prior to theapplication of coin battery to the telephone line from the telephonecentral office, insufficient current was available for operation of coinrelay 110, although sufficient current was available for operation ofthe light emitting diode that was included in optical isolator 140.Operation of the coin relay 110 restores coin trigger springs 111 and112 to their normal position. At this time the coin operated telephoneis fully restored to normal and is ready for placement of additionalcalls over its facility.

If after the subscriber has deposited one or more coins in the cointelephone, he decides not to complete the call, and the total of thecoins deposited is not equal to the established base rate, the followingsequence of events take place. To abandon the call the subscriber willplace his hand set including transmitter 105 and receiver 104 in itsnormal position on hook switch 102 causing it to restore. Therestoration of hook switch 102 opens the loop connection to thetelephone central office, causing the central office telephone equipmentto return coin battery over the lead connected to terminal T. This coinbattery is conducted from terminal T through neon diode 175 and resistor174 to the optical isolator and particularly to the light emitting diodethat forms a portion thereof, and from there to coin relay 110 andthrough coin trigger springs 111 to ground. Application of coin batteryover this path causes operation of the photo transistor that is includedin the optical isolator 140 which will cause application of potential tocounter 160, causing it to reset back to zero. The operation of counterto its reset position causes an output on the zero terminal lead whichthrough gate 172 and capacitor 173 will cause rate relay 170 to restore.The restoration of relay 170 completes a direct connection at breakcontacts 171 from the conductor connected to the T lead to the opticalisolator 140. With the restoration of rate relay 170 and the restorationof it associated contacts 171, resistor 174 and neon diode 175 are nolonger in the circuit, and sufficient current is available to cause coinrelay 110 to operate. With the operation of coin relay 110 thepreviously deposited coins will be refunded and the present cointelephone returns to its normal arrival condition.

It should be noted that the totalizer circuit 100 derives its powerdirectly from the telephone line connected to the telephone centraloffice. A self contained power supply consisting of diodes 121 through126, resistors 131 and 132 capacitor 133 and zener diode 134 provide asource of power for the circuitry of the totalizer.

To provide this power a connection from terminal T connected to thetelephone central office through dial 101 is made to the junctionbetween diodes 121 and 122 the return path is made from the terminal Rconnected to the telephone central office through resistor 131 to thejunction of diodes 123 and 124. The four diodes 121 through 124inclusive function as a full-wave rectifier whose output is utilized asrequired. The above outlined circuitry is employed power the totalizercircuit when the'present coin operated telephone is in its normal oron-hook" position.

When the telephone is in the operated or "off-hook" position the poweris drawn from the telephone central office in similar matter except thata return path is also provided through resistor 132 which is connectedbetween the junction of diodes 125 and 126, through operated switch hook102 to the lead connected to terminal R. This additional path provides ahigher source of available energy when the telephone hand set has beenremoved from the hook switch. It should be noted that in the presentcircuitry, a requirement exists that power be available from thetelephone central office at all times in order to provide operatingpower for the totalizer 100. If totalizer 100 were not prepowered, itwould be possible to operate the coin trigger springs and thus completea call to the telephone central office with deposit of but a single coinof any denomination.

In the above description it should be noted that reference has been madeto deposit of nickels and dimes to achieve the base rate required foroperation of the present coin telephone. If a subscriber were to drop aquarter in the coin slot of the coin telephone, coin trigger springs 111and 112 would operate, however counter 160 would not operate andaccordingly the telephone would be in condition for placement of a call.This reflects the fact that a quarter is equal to or exceeds theestablished base rate requirement.

SEMl-POSTPAY OPERATION Referring now to FIG. 2 a totalizer in accordancewith the present invention is shown in a coin operated telephoneequipped for semi-postpay operation. The circuitry of the totalizer issimilar to that of the previously described unit with three digitnumbers beginning with 2 generally identifying circuit elements likethose in FIG. 1 which begin with the digit 1. The telephone circuitry isalso essentially similar except that a different form of coin relay isincorporated in the semipostpay form of coin operated telephone. Thecircuitry of the totalizer 200 for a semi-postpay coin operatetelephone, distinguishes from that of the totalizer shown in FIG. 1 byits omission of two diodes 123 and 124 and associated resistor 131,optical isolator and the resistor-neon lamp combination 174 and 175respectively. The remaining circuitry being identical to that shown inFIG. 1.

In the coin telephone circuitry it should be noted that the coin relayis a two coil unit consisting of coin relay coils 210A and 2108 eachwith separate associated spring contacts. Associated with coil 210A isdouble make spring contacts 216 while associated with coil 2108 arebreak contacts 217 and make contacts 218. A single coin trigger 211, isalso employed in this embodiment. It should be further noted that coinrelay 210 is polarized with coil A operating its associated contacts inresponse to reverse battery before coins are deposited and releasingafter the first coin has been deposited. Coil 2l0B operates itsassociated contacts 217 and 218 after the first coin has been depositedand when reverse battery is present. The coin trigger 211 resets inresponse to normal battery conditions.

A subscriber wishing to make a call removes the hand set from the hookswitch 202 which completes the loop to the telephone central officethrough terminal T, dial 201, transmission network 203 coin relaysprings 217 and coin relay coil 210A, and then through the hook switch202 to terminal R connected to the telephone central office. At thistime dial tone is returned to the subscriber and the dial can beoperated to establish the desired connection through the telephonecentral office.

When the connection is established to the dialed number, if the dialselection is to an operator or to an emergency number, reverse batterywill not be returned and conversation may ensue in the usual manner. Ifhowever this is not a special service call of any sort on the connectionbeing established, reverse battery will be returned from the telephonecentral office causing coin relay coil 210A to operate. This operationat contacts 216 places a direct short across transmitter 205 and a lowimpedance shunt through resistor 219 across the transmission network toprevent the subscriber utilizing the receiver 204 as a transmitter. Ifthe called subscriber answers, the calling subscriber utilizing thepresent coin telephone will hear the answering subscriber via thereceiver 204. On determining that he has reached the desired party, thecoin telephone user will deposit coins having a predetermined totalvalue equalling the established base rate in use for the present cointelephone.

Deposit of coins totalling or exceeding in monetary value thepredetermined value established, will remove the low impedance shuntfrom transmission network 203 and the direct short across transmitter205, so that conversation may ensue.

The details of operation of the totalizer circuit 200 can best beunderstood by the following description: initially assume that thecalling subscriber has deposited a single nickel. In response to thedeposit of the initial nickel, coin operated switch 213 will operate andthrough NOR gate 250 advance counter 260 from its zero output to the 59! terminal output position. Since no signal is available from thatterminal and the output on the zero terminal is removed, the resultingoutput from NOR gate 272 through capacitor 273 will cause rate relay 270to operate. Operations of rate relay 270 at contacts 271 prepares ashunt path directly across the transmission network.

Deposit of the initial nickel will also operate coin trigger springs 211resulting in operation of coin relay coil 2108 and its associatedcontacts 217 and 218. When contacts 218 close the shunt path across thetransmission network previously outlined affectively disables bothreceiver 204 and transmitter 205. At contacts 217 the operating path forcoin relay coil 210A is opened causing contacts 216 to restore,preparing the transmission circuitry of the telephone for operation atsuch time as coins totaling in value the predetermined base rate havebeen deposited.

Deposit of additional coins whose monetary value is equal or greaterthan the 20 base figure. causes the counter 260 to advance and throughgate 272 to cause rate relay 270 to restore. Restoration of rate relay270 at contacts 271 removes the direct short across the transmissionnetwork. At this point conversation may ensue.

On completion of the call the subscriber will return the hand set tohook switch 202 opening the loop to the telephone central office.

When initial connection is made to the telephone central office,potential present at termainl T from telephone central office isconducted by way of the reset lead to the decimal counter 260. Thispotential is effective to automatically reset the counter 260 to itszero state. which will cause application at terminal zero of an outputto gate 272 which through coupling capacitor 273 cause rate relay 270 torestore.

While preferred embodiments of the present invention only, have beenshown, it will be obvious that numerous modifications may be madewithout deparing from the spirit and scope of the invention, which shallbe limited only be the claims appended hereto.

What is claimed is:

l. A coin operated telephone instrument adapted for connection to atelephone central office by means of a telephone line, including atransmitter, a receiver, a calling device, a coin detecting mechanismnormally inhibiting conversation between said instrument and a selectedsubscriber station of the type requiring deposit of at least one coin insaid telephone instrument equivalent in total value to a predeterminedvalue, said coin detecting mechanism operated in response to deposit ofa first coin of any value to condition said instrument for conversationwith said selected subscriber station, and a totalizer, said totalizercomprising: counting means electrically advanced once in response todeposit of each coin of a first value and electrically advanced twice inresponse to deposit of each coin of a second value, said counting meansinitially operated to generate a first output in response to a firstadvance and further operated to generate a second output in response toa predetermined number of additional advances; switching means connectedto said counting means initially operated in response to said countingmeans first output to further inhibit conversation between saidinstrument and said selected telephone subscriber station, and furtheroperated in response to said counting means second output to permitconversation between said instrument and said selected telephonesubscriber station.

2. A coin operated telephone instrument as claimed in claim 1 wherein:said counting means further operation inhibits further advance of saidcounting means.

3. A coin operated telephone instrument as claimed in claim 1 wherein:said counting means comprise a decimal counter and logic circuitry, saidlogic circuitry operated in response to deposit of a coin of a firstvalue to generate a single output pulse to advance said counter once,and in response to deposit of a coin of a second value to advance saidcounter twice.

4. A coin operated telephone instrument as claimed in claim 1 wherein:said switching means comprise a relay.

5. A coin operated telephone instrument as claimed in cairn 1 wherein:said coin detecting mechanism is operated in response to deposit ofafirst coin of any value to prepare an operating circuit for saidinstrument, said switching means initial operation opening saidoperating circuit, and said switching means further operation completingsaid prepared operating circuit.

6. A coin operated telephone instrument as claimed in claim 5 wherein:there is further included reset means included in said operatingcircuit, operated in response to said operating circuit completion, toreset said counting means.

7. A coin operated telephone instrument as claimed in claim 1 wherein:said coin detecting mechanism initially completes a first shunt circuitaround said calling device, and in response to deposit of a first coinof any value opens said first shunt circuit; said switching meansinitial operation completing a second shunt circuit around said callingdevice and said switching means further operation removing said secondshunt from said calling device.

.8. A coin operated telephone instrument as claimed in claim 1 wherein:said coin detecting mechanism is initially operated in response toconnection of said instrument to a selected subscriber station of thetype requiring deposit of at least one coin in said telephone instrumentequivalent in total value to a predetermined value, to complete a firstshunt circuit around said transmitter; said switching means initialoperation preparing a second shunt circuit around said transmitter andaround said receiver; said coin detecting mechanism further operated inresponse to deposit of a first coin of any value, to complete saidsecond shunt circuit; and said switching means further operationremoving said second shunt circuit.

9. A coin operated telephone instrument as claimed in claim 8 wherein:there is further included reset means comprising a circuit connectionbetween said counting means and said telephone line, said reset meansoperated in response to connection of said instrument to said centraloffice, to reset said counting means.

1. A coin operated telephone instrument adapted for connection to atelephone central office by means of a telephone line, including atransmitter, a receiver, a calling device, a coin detecting mechanismnormally inhibiting conversation between said instrument and a selectedsubscriber station of the type requiring deposit of at least one coin insaid telephone instrument equivalent in total value to a predeterminedvalue, said coin Detecting mechanism operated in response to deposit ofa first coin of any value to condition said instrument for conversationwith said selected subscriber station, and a totalizer, said totalizercomprising: counting means electrically advanced once in response todeposit of each coin of a first value and electrically advanced twice inresponse to deposit of each coin of a second value, said counting meansinitially operated to generate a first output in response to a firstadvance and further operated to generate a second output in response toa predetermined number of additional advances; switching means connectedto said counting means initially operated in response to said countingmeans first output to further inhibit conversation between saidinstrument and said selected telephone subscriber station, and furtheroperated in response to said counting means second output to permitconversation between said instrument and said selected telephonesubscriber station.
 2. A coin operated telephone instrument as claimedin claim 1 wherein: said counting means further operation inhibitsfurther advance of said counting means.
 3. A coin operated telephoneinstrument as claimed in claim 1 wherein: said counting means comprise adecimal counter and logic circuitry, said logic circuitry operated inresponse to deposit of a coin of a first value to generate a singleoutput pulse to advance said counter once, and in response to deposit ofa coin of a second value to advance said counter twice.
 4. A coinoperated telephone instrument as claimed in claim 1 wherein: saidswitching means comprise a relay.
 5. A coin operated telephoneinstrument as claimed in caim 1 wherein: said coin detecting mechanismis operated in response to deposit of a first coin of any value toprepare an operating circuit for said instrument, said switching meansinitial operation opening said operating circuit, and said switchingmeans further operation completing said prepared operating circuit.
 6. Acoin operated telephone instrument as claimed in claim 5 wherein: thereis further included reset means included in said operating circuit,operated in response to said operating circuit completion, to reset saidcounting means.
 7. A coin operated telephone instrument as claimed inclaim 1 wherein: said coin detecting mechanism initially completes afirst shunt circuit around said calling device, and in response todeposit of a first coin of any value opens said first shunt circuit;said switching means initial operation completing a second shunt circuitaround said calling device and said switching means further operationremoving said second shunt from said calling device.
 8. A coin operatedtelephone instrument as claimed in claim 1 wherein: said coin detectingmechanism is initially operated in response to connection of saidinstrument to a selected subscriber station of the type requiringdeposit of at least one coin in said telephone instrument equivalent intotal value to a predetermined value, to complete a first shunt circuitaround said transmitter; said switching means initial operationpreparing a second shunt circuit around said transmitter and around saidreceiver; said coin detecting mechanism further operated in response todeposit of a first coin of any value, to complete said second shuntcircuit; and said switching means further operation removing said secondshunt circuit.
 9. A coin operated telephone instrument as claimed inclaim 8 wherein: there is further included reset means comprising acircuit connection between said counting means and said telephone line,said reset means operated in response to connection of said instrumentto said central office, to reset said counting means.